Chain grate.



W. M. DUNCAN.

CHAIN GRATE. APPLICATION FILED DEC. 21, 1911.

1,04 ,053, H Patefited Dec. 24, 1912.

mvanhov %Dunoan 4 7%6 Abb'Y.

UNITED srirrns Parana? @FFEQEZ.

' WILLm aQM. Duncan, or ALTON, rumors.

CHAIN Gears.

Specification of Letters Patent.

Patented Dec. 2 42,

Application filed Eecember 21, 1911. Serial Ne. 667,187.

stokers, and it has as a particular object the construction of a grate of this description especially useful for the support and movement of coking fuel, such as coal, in a manner to break up the mass of fuel at intervals for the facilitation of combustion therein.

Figure I is a top or plan View of my chain grate. Fig. II is a side elevation of the grate partly broken out, Fig. III is an enlarged top or plan view of a fragment of the grate. Fig. IV is a vertical cross section taken'on line IV-IV, Fig. III.

In the drawingsz-l designates the side frames of my grate. Inthe preferred construction of the grate, I utilize at the rear end thereof a supporting shaft 2 journaled in the side frames 1 and equipped with a plurality of idler wheels 3 under which the chains of the grate travel when moving in a reverse course after partaking-of movement in a direction toward the rear end of the grate. At the opposite or front end of the grate are two independently movable inner and outer drive shafts 4 and 5 having fixed thereto drive wheels similar to the idler Wheels 3 by which the chains of the grate are operated.

' 6 and 7 are chains composed of grate bars of the kind commonly employed in chain grates, the variouslbars entering into the chains being pivotally' connected in a manner to permit'fiexing of the chains as they pass around the supporting idler drive wheels on which they operate. The chains 6 are arranged in engagement with the inner Wheels on the inner drive shaft 41. and the chains 7 are arranged in engagement with the outer wheels on the outer drive shaft 5, and said chains are arranged alternately of each other transversely of the,

' grate, as seen in Fig. I. It will, therefore,

be seen thatone series of the-chains maybe operated at one timeand the other series intermittent of chains operated at another time through the medium of the two separate inner and outer drive shafts 4c and 5. Each of the grate bar chains preferably comprises grate bar units containing a plurality of grate bars arranged side by side and united by transverse connecting members, as seen in Fig. IV, where three grate bars are shown connected by a pin passing transversely therethrough.

As preferred of moving the inner and outer drive shafts 4 and 5 independently of each other and intermittently in order that a desired result of moving the grate bar chains intermittently may be accomplished, I employ the shaftcperating means illustrated in the drawings. The inner and outer drive shafts t and 5 have fixed to them, respectively, worm wheels 8 and 9- that are'engaged by worms l0 and 11 carried by shafts journaled in suitable'suppor'ts located adjacent to said worm wheels; the left worm 1O pushing. down and the right worm -11 pushing up on their respective worm Wheels. 11 are provided respectively withratchet wheels 12 and 13, that receive the engagement of pawls la and 15 carried by rockable arms 16 and 17. The pawl carrying arms are pivoted to' a reciprocating bar 18 that is operable by an eccentric 19 on a shaft the alternately arrangedgrate bar chains.

6 and 7 is, therefore, shifted in a forward direction to the ear end of the 'grate at one time by one sel of the grate oar chains, and

shortly thereafter in the same forward di v rection to the rear end of the grate by an other set of grate bar chains: and, as a consequence, it is frequently disturbed by an shuffling movement of the chains, resulting in the breaking up of the The worm shafts 10 and 20, whichmay be driven by power applied.

fuel mass instead of allowing said mass to become solidified and remain in such c0ndition, to the detriment of the entrance of oxygen thereinto for the promotion of combustion.

I claim 1. A chain grate comprising a plurality of sets of endless grate bar chains furnishing a single grate surface, the chains of one set being arrangecl alternately between chains of the other set, a separate drive shaft for operating each set of grate bar chains in one general direction, and (iriving mechanism for said. shafts, said driving mechanism comprising means for operating one of said shafts While the other shaft is idle.

2. A chain gi'ste compri ing a pluralit of sets of endless grate bar chains furnishing s single grate surface, the chains of one 2) set hein' arranged alternately between chains 0' the other set, s drive shaft for each set of grate bar chains, and means for operating first one and then the other of said shafts, whereby the sets of grate bar 2-; 

